diff --git a/contrib/test.sh b/contrib/test.sh
index 3af30079..be039354 100755
--- a/contrib/test.sh
+++ b/contrib/test.sh
@@ -9,7 +9,14 @@ rustc --version
 
 # Pin dependencies required to build with Rust 1.48
 if cargo --version | grep "1\.48"; then
+    cargo update -p serde_json --precise 1.0.99
     cargo update -p serde --precise 1.0.156
+    cargo update -p once_cell --precise 1.13.1
+    cargo update -p regex --precise 1.7.0
+    # These two needed for serde_derive with 1.48.0, *in addition*
+    # to pinning serde itself above.
+    cargo update -p quote --precise 1.0.30
+    cargo update -p proc-macro2 --precise 1.0.65
 fi
 
 # Format if told to
diff --git a/src/policy/concrete.rs b/src/policy/concrete.rs
index d696b53a..97ff05f6 100644
--- a/src/policy/concrete.rs
+++ b/src/policy/concrete.rs
@@ -662,6 +662,7 @@ impl<Pk: MiniscriptKey> ForEachKey<Pk> for Policy<Pk> {
     where
         Pk: 'a,
     {
+        let mut pred = |x| pred(x);
         match *self {
             Policy::Unsatisfiable | Policy::Trivial => true,
             Policy::Key(ref pk) => pred(pk),
diff --git a/src/policy/semantic.rs b/src/policy/semantic.rs
index cd6080fe..1dbb30a9 100644
--- a/src/policy/semantic.rs
+++ b/src/policy/semantic.rs
@@ -64,6 +64,7 @@ impl<Pk: MiniscriptKey> ForEachKey<Pk> for Policy<Pk> {
     where
         Pk: 'a,
     {
+        let mut pred = |x| pred(x);
         match *self {
             Policy::Unsatisfiable | Policy::Trivial => true,
             Policy::Key(ref _pkh) => todo!("Semantic Policy KeyHash must store Pk"),